1. Field of the Invention
This invention relates to the field of marine equipment, and more particularly to systems for reefing sails on sailboats.
2. Description of the Related Art
Reefing is a procedure used in sailing for reducing the area of a sail on a sailboat or sailing ship. Reefing can improve the boat's stability and reduce the risk of capsizing, broaching, or damaging sails or boat hardware in strong winds.
There are three common methods of reefing: slab reefing, conventional dual line and single line reefing, and in-mast and in-boom mainsail reefing.
Slab Reefing
Slab reefing systems require the sailing vessel's crew to leave the cockpit and perform the mainsail reef while standing at the mast. Using this system, the leading edge (luff) of the mainsail must be pulled down to the boom by hand and secured manually to a gooseneck fitting or similar S-hook attachment on the forward end of the boom. The trailing (leech) end of the mainsail must then be hauled down to the boom by pulling on a separate reefing line.
Perhaps the biggest drawback to slab reefing is that it requires at least one crewmember to leave the cockpit and go to the mast. This can be a potentially hazardous maneuver, especially if it is undertaken at night and/or in rough and slippery conditions, as is usually the case when the wind has increased to a point where a deep mainsail reef is warranted.
With a slab reefing system, the location of the reefing winch can also present problems for the crew. For example, if the reefing winch is located on the boom on the downwind, or “leeward” side of the vessel during a reefing operation, the crew will be forced to operate the winch from the downwind side of the vessel. This position can be awkward and dangerous, since the leeward side of a sailing vessel is typically heeled to a steep angle and is often awash with wave action during windy conditions.
Furthermore, slab reefing requires the crew to haul in a long length of reefing line to complete the reef. This is because the slab reefing line must be doubled through the reef cringle on the leech end of the sail in order to provide the leverage needed during the outhaul tensioning phase of the reefing procedure.
Clearly, there is a need for less potentially hazardous reefing procedures. Furthermore, there is a need for reefing systems that do not necessitate pulling in such a long length of line.
Dual Line and Single Line Reefing Systems
Unlike slab reefing systems, conventional dual line and single line reefing systems do not require the crew to leave the cockpit to deploy a mainsail reef. However, a dual line reefing system requires that two reefing lines be led to the cockpit for each reef. Moreover, both dual and single line reefing systems require the crew to pull in long lengths of line. For example, a so-called “Hoyt” single line reefing system, see U.S. Pat. No. 4,487,147 to Hoyt, would require the crew to haul in almost one hundred feet (100′) of line in order to complete a triple reef on a mainsail with an overall surface area of approximately four hundred square feet. Furthermore, a Hoyt single line reefing system, since it consists of only one line, places the entire mechanical load generated by the reefing process and by the forces of the wind onto that single line. These potential loads are high enough so that a Hoyt single line reefing system is generally limited to use on sailing vessels under thirty-two feet in length.
Clearly, there is a need for reefing systems which do not require the crew to pull in such long lines. Furthermore, there is a need for single line systems which do not place such a large load on the line.
In-Mast and In-Boom Mainsail Reefing Systems
In-mast mainsail reefing systems are designed to roll the mainsail “venetian blind” style around a rotating rod inside the mast. These systems require that the mainsail be constructed without sail battens, so that the sail can be rolled up either directly behind or inside the mast itself. The elimination of battens constitutes a significant performance loss, since without battens the sail cannot hold an ideal aerodynamic shape in a variety of wind conditions.
Moreover, both in-mast and in-boom reefing systems—where the mainsail is rolled around a full-length rod inside the boom instead of inside the mast—require the elimination of mainsail roach, which significantly reduces the total available surface area of the mainsail and consequently reduces overall sail performance.
In-mast and in-boom mainsail reefing systems are expensive and complicated to install. This is largely because of the requirement for custom built masts, booms, and mainsails for the successful installation of these systems.
Furthermore, if an in-mast furling system should jam for any reason, the mainsail could become stuck in the raised position. In a gale at sea, this situation could be analogous to a stuck accelerator in a car, with no easy solutions at hand.
In conclusion, there is a need for reefing systems that provide safe, cost effective and efficient means for reefing a sail.